The present invention relates to a capacitor element and a battery cell which are especially excellent in the ability to keep electrolyte solution and have small internal resistance.
According to the conventional capacitor element and battery cell constituting electric double layer capacitor, electrolyte solution has been used. In this capacitor element and battery cell, the ability to keep electrolyte solution is a major factor to decide a life. Therefore various ideas have been applied to keep the electrolyte solution.
For example, the Japanese Patent Laid-Open Publication No. HEI 7-240348 discloses the capacitor element of the electric double layer capacitor having a means for restraining dry-up by forming an amorphous silica particle layer or an alumina particle layer in the minute holes of the porous separator and concentrating the electrolyte solution. This capacitor element is constituted of a porous separator which has ion permeability and the ability of insulation, a pair of carbon paste electrodes containing an aqueous solution type electrolyte separated by this porous separator, a non-conductive gasket holding these carbon paste electrodes at the surrounding ends of these carbon paste electrodes and a pair of conductive separators holding the carbon paste electrodes and the non-conductive gasket from the outside. In this capacitor element, the amorphous silica particle layer or the alumina particle layer and aqueous solution type electrolytic solution are concentrated on the minute hole wall of the porous separator.
An electrolytic capacitor providing a means for restraining dry-up of electrolyte solution of the electrolytic capacitor is disclosed in the Japanese Patent Laid-Open Publication No. SHO 50-66761 and No. SHO 60-254721 and Japanese Patent Publication No. SHO 63-54208. These electrolytic capacitors all have a gel electrolyte solution.
However, in the conventional capacitor element, there is a problem that internal resistance is large caused by that the concentration of the electrolyte solution makes the degree of movement of ion short.
It is therefore an object of the present invention to provide a capacity element and a battery cell having characteristics which a dry-up phenomenon is restrained and an internal resistance is small.
To solve the above mentioned problems, the capacitor element of the present invention provides a porous separator which has ion permeability and the ability of insulation, a pair of carbon electrode layers having many successive through holes separated by said porous separator, a non-conductive gasket holding the surrounding ends of said carbon electrode layers, a pair of conductive separators holding said carbon electrode layers and said non-conductive gasket from the outside, electrolyte solution in said successive through holes of said carbon electrode layers, and minute particles which are more than 0.1 weight % and less than 5.0 weight % of said electrolyte solution in said successive through holes of said carbon electrode layers.
The battery cell of the present invention provides a porous separator which has ion permeability and the ability of insulation, a positive electrode active material layer and a negative electrode active material layer having many successive through holes separated by said porous separator, a positive electrode current collector and a negative electrode current collector connecting to said positive electrode active material layer and said negative electrode active material layer, electrolyte solution in said successive through holes of said positive electrode active material layer and said negative electrode active material layer, and minute particles which are more than 0.1 weight % and less than 5.0 weight % of said electrolyte solution in said successive through holes of said positive electrode active material layer and said negative electrode active material layer.